{
  "abstract": "Atmospheric refractivity and its vertical changes play an important role in how radio waves travel, but detailed studies across different climate regions are still limited. This study provides a long-term analysis of refractivity, its vertical gradients, and k-factor changes across five major climate zones: tropical, arid, temperate, subarctic, and polar. Using several decades of atmospheric data, we analyse vertical structures, seasonal patterns, year-to-year changes, and extreme conditions, and relate them to physical processes in the atmosphere that affect radio-wave behaviour. The results show that tropical regions have the strongest negative refractivity gradients near the surface (– 54.6 N/km) and the highest occurrence of super-refraction, mainly due to the combined effects of high humidity and temperature, especially during wet-season convection. In contrast, arid and polar regions are mainly influenced by temperature, showing more frequent sub-refraction and weaker seasonal changes. Temperate and subarctic regions show mixed characteristics, influenced by both moisture and temperature layering. In addition, we provide a direct evidence for the influence of large-scale climate variability, particularly El Niño, on refractivity gradients. Specifically, we examined the relationship between the refractivity gradient and the Niño 3.4 Index, and a clear correspondence between the temporal variations of the refractivity gradient and the Niño 3.4 Index is observed, providing independent support for our interpretation and strengthening the link between ENSO-related climate variability and refractivity gradient changes. We also demonstrate the effect of surface-pressure masking on refractivity gradient estimates. These findings highlight the need for climate-specific refractivity models and provide useful guidance for improving radio-wave prediction and communication system design in different environmental settings.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Physics, College of Agriculture, Engineering, and Science, Bowen University",
    "Department of Physics, University of Ilorin"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 5,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Solomon O. Adeola"
    },
    {
      "affs": [
        0
      ],
      "name": "Jacob A. Akinpelu"
    },
    {
      "affs": [
        0
      ],
      "name": "Francis O. Aweda"
    },
    {
      "affs": [
        1
      ],
      "name": "Saeed A. Bello"
    },
    {
      "affs": [
        0
      ],
      "name": "Nathaniel O. Adeniji"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/eyx2wa132fea4.bib",
  "cited_by": 1,
  "doi": "10.1038/s41598-026-62512-4",
  "fulltext_url": "https://doi.org/10.1038/s41598-026-62512-4",
  "id": "eyx2wa132fea4",
  "issns": [
    "2045-2322"
  ],
  "landing_url": "https://doi.org/10.1038/s41598-026-62512-4",
  "language": "en",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "lcc",
      "Q"
    ],
    [
      "lcc",
      "R"
    ],
    [
      "openalex",
      "2202|Radio Wave Propagation Studies"
    ]
  ],
  "openalex": "W7170796163",
  "pdf_url": "https://www.nature.com/articles/s41598-026-62512-4_reference.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-07-01",
  "publisher": "Nature Portfolio",
  "ris": "https://research.draconitic.com/paper/eyx2wa132fea4.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T13:45:56Z",
      "native_id": "33f084bd4f6c46ed9d9d43c9de4f9244",
      "source": "doaj",
      "url": "https://doi.org/10.1038/s41598-026-62512-4"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "lcc:R",
      "subfield": "general"
    }
  ],
  "title": "A 31 year analysis of long-term variability of atmospheric refractivity and gradients from tropics to poles",
  "title_text": "A 31 year analysis of long-term variability of atmospheric refractivity and gradients from tropics to poles",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T13:45:56Z",
  "url": "https://research.draconitic.com/paper/eyx2wa132fea4",
  "venue": "Scientific Reports",
  "versions": []
}